1. Field of the Invention
The present invention relates to an intermediate transferrer and an image forming apparatus including the intermediate transferrer.
2. Description of Related Art
An image forming apparatus transfers a toner image formed on a photoreceptor to an intermediate transferrer, and then transfers the toner image to a recording medium such as plain paper. The intermediate transferrer is, for example, an endless intermediate transfer belt including an elastic layer for enhancing the contact property to the photoreceptor or the recording medium, and a surface layer for suppressing abrasion of the elastic layer. From the viewpoint of preventing the surface layer from being peeled off from the elastic layer due to stress during the transfer, the adhesive property between the elastic layer and the surface layer is preferably high. From the viewpoints of enhancing the adhesive property between the elastic layer and the surface layer, and the like, intermediate transferrers that employ a metal coupling agent has been known (e.g., Japanese Patent Application Laid-Open No. 10-10896, Japanese Patent Application Laid-Open No. 9-292767, and Japanese Patent Application Laid-Open No. 4-19761).
In the intermediate transferrer disclosed in Japanese Patent Application Laid-Open No. 10-10896, an inorganic filler treated with a silane coupling agent containing perfluoroalkyl groups is dispersed in a surface layer. Further, in the intermediate transferrer disclosed in Japanese Patent Application Laid-Open No. 9-292767, an intermediate layer composed of a silane coupling agent capable of reacting with an SiH group in an elastic layer is disposed between the elastic layer and a surface layer. Furthermore, in the intermediate transferrer disclosed in Japanese Patent Application Laid-Open No. 4-19761, the surface of an elastic layer is coated with a titanate-based coupling agent or an aluminum-based coupling agent to form a surface layer.
However, both in the intermediate transferrers disclosed in Japanese Patent Application Laid-Open No. 10-10896 and Japanese Patent Application Laid-Open No. 4-19761, the elastic layer and the surface layer are not adhered by chemical bonding, and thus the adhesive property between the elastic layer and the surface layer is not sufficient. Further, in the intermediate transferrer disclosed in Japanese Patent Application Laid-Open No. 9-292767, the elastic layer and the intermediate layer are adhered by chemical bonding via an SiH group in the elastic layer, but the intermediate layer and the surface layer are not adhered by chemical bonding. Consequently, also in the intermediate transferrer disclosed in Japanese Patent Application Laid-Open No. 9-292767, the adhesive property between the elastic layer and the surface layer is not sufficient.
Moreover, when an elastic layer is coupling-treated with a silane coupling agent, in general, a hydroxyl group is required to be present in a portion of the elastic layer, which serves as a surface to be treated, in order for the elastic layer and the silane coupling agent to be chemically bonded to each other. When a material that has no hydroxyl group constitutes a surface to be treated, performing a treatment for generating a hydroxyl group (e.g., corona treatment) on the surface to be treated may result in deterioration of the material constituting the elastic layer in some cases.